Cushioned gear



July 17, 1951 T. L. FAwlcK CUSHIONEII? GEAR 2 Sheets-Sheet 1 Original Filed April 27, 1945 July 17, l951 T. L. FAwlcK 2,561,103

CUSHIONED GEAR Original" Filed April 27, 1945 2 Sheets-Sheet 2 om, de

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N nw E Mw ATTORNEY Patented July 17, 1951 CUsHIoNED GEAR Thomas L. Fawick, Cleveland, Ohio` Original application April 27, 1945, Serial No.

590,692. Divided and this application July 24, 1946, Serial No. 686,013

2 Claims. l

This invention relates to cushioned gears.

. Its chief objects are to provide an improved gear having cushioning means interposed between itstoothed portion and its hub or the portion that is' adapted to be engaged with a mounting forl the gear; to provide accuracy in the cutting of the gear teeth in spite of such eccentricity as may result from the interpositioning of the cushioning means before the teeth are cut; and to provide a gear comprising natural rubber as the cushioning means with improved provision for protecting the rubber from contact with oil.

Other' objects are to provide a cushioned gear assembly lhaving a pitch diameter not r'nuch greater than the diameter of a shaft which is a part of theA assembly, and to provide such a gear with provision for transmission of heavytorque. The present application is a division of mycopending application Ser. No. 590,692, led April 27, 1945, now Patent Number 2,483,267, September 27, 1949. .'.Of the accompanying drawings: I Fig. l is an axial section, with the shaft. or hubvin elevation, of a gear embodying and made in accordance with my invention' in its preferred form. I

,- Fig. 2 is a similar view of the shaft or hub merli-I ber and cushioning means thereon as they appear at one stage of the process.

Fig. 3 is an axial section of another embodiment of the invention, with provision for transmission of heavy torque.

Referring to the embodiment illustrated in Figs. 1 and 2 of the drawings, a shaft l@ rst has mold vulcanized upon and adhered to it a set of spaced apart, deformable rings, the end rings, I I, II, being of oil-resistant synthetic material such as neoprene, Chlor-butadiene, polymerized vinyl chloride or co-polymers of vinyl chloride and vinyl acetate, and the intermediate rings I2, I 2 being of a composition comprising natural rubber, of about the characteristics of tire-tread rubber, for its long-lasting cushioning eTect.

The shaft with the deformable rings thereon is then forced lengthwise, in a procedure Well known in the art, into a metal sleeve or gearblank I3 which ultimately becomes the toothed portion of the gear, and the dimensions are such that this operation deforms the rings so that they substantially ll the space between the shaft and the gear-blank, their shape and relation then being as shown in Fig. l.

The gear blank I3 preferably is preformed with a cylindrical counterbore I4 in each end and, after the assembly of the gear-blank with the shaft and its cushioning rings, which may result in some eocentricity of the blank in relation to the shaft, the cylindrical wall of each counterbore is lightly cui-l or ground, as by mounting the shaft inra lathe, to make the wall truly concentric withv the shaft when the cushions are substantially free from extraneous forces acting between the sleeve and the shaft, and to make it of proper diameter to receive the accurately sized end portion of a spacing collar I5 having upon it an oufwardly projecting stud IS'adapted to i'lt into an open-end slot` II formed in the end margin of the gear blank, and provided with a pair of setscrews-I8, I8 for securing it upon the shaft.

The gear blank thus being held firmly in such relationship to the shaft as is determined by the balance of the forces in the deformed cushioning rings, the set of gear teeth, I9, I9, are formed uponit, while it is so held. l rThen the spacing collars I5 are removed from the assembly, and, if desired, the annular end margins of the gear-blank, to the depth of the counterbore, can be cut off, at the lines X-X, and

f discarded.

The resulting assembly is such that the set of teeth are concentric With the shaft when the cushioning members are in a condition of balanced stresses, and the cushioning action of the gear has its start from that condition.

In the embodiment shown in Fig. 3, the shaft Ia is of waisted form in the region of the resilient rings, IIa and I2a, but the procedure for assembling the shaft and its resilient rings with the gear blank, I3a, and holding the latter in position While the gear teeth, I9a, are cut in concentric relation to the shaft, is substantially the same as that described With reference to Figs. 1 and 2, but while the gear blank is so held it is formed also, at each end, with a set of splines 20, 20, each set being adapted to receive a set of complemented internal splines formed in a driving ring 2l.

Each of the driving rings 2| is formed with a circumferentially spaced set of threaded holes for the threaded stems of a set of studs 22, 22, each having secured by vulcanized adhesion on its relatively large cylindrical head a cushioning ring or bushing 23 of rubber-like material which is held under radial compression by a surrounding metal bushing 24, the three members 22, 23 and 24 being assembled as above described with reference to the members Ill, Il, I2 and I3 of Figs. 1 and 2.

The outer surface of each of the metal bushings 24 can be lightly cut or ground, after asplication. Serialv No. 587,892, iiled April- 12 1.945,... now Patent,Number"2,460,630, issued Fbrluaryu 1;,v

to sustain heavier torque than that showmin,

Fig. 1, by reason of the. fact that the cushions 23. of Fig. 3 sustain the torque in compression instead`- of" only in shear', and* because" they aref* atg a relatively largeradiusfrom the axisrof" rotai-v tion. As.' the members f23` cushion thetorque'with'l relatively high-resistance and consequently with?- out' great" deformation, the-cushioning rings'k lil yIZJiinFig:` Siserve chiefly forfcent'eriii'g tlieteethf i921, an'dfor insulating' against transmission" of? vibration orfs'ound, as they andftheirubb'er liishwings.i Zcomplete' insulatel thef gear 'teeth fr'c'imA the' shattil They invention providesl the advantagesf that' are Is e't'out in thefabo've statement offobjects-landmodicationsf are possiblewithout sacric'ofall of those advantages and without i'departure fiomthefscope 'of the appended =claims.- Irre theA`v language of't the appended clainis the; s'liaftvl" in Figl' or' [Ud inl Fig. 3; is-the mount#v igfoftheltoothed' ring" |3f-or- I3'a'; in Fig. Btl'i'e members 2l, 22, 23, 24; 25fand'26", adapted" to share the torque load? with` the cushioning rings IZ; on' occasion, are-the rotativelyinterlocking means (as distinguished'from means dependent pon adhesion orf frictiona'l'- grip)= interposed operatively between, although not physi' `:a'lly`he#v tween, the `toothed gear ring'f and the fsha'ft l; A- cushioned gear assembly' corripri'sir'igJv a rigid hub member, a rigid toothed gear ring surrounding the hub member and therewith defining an annular space, cushioning means in said space and having engagement with the hub member and the ring for transmission of torque between the two, a rigid drive member directly splinedto the .toothed ring andofL greater radial extent tha-'ni'.the tooth portion of thefring a rigid drive member secured on the hub member in close proximity to the first said drive member,

and cushioning means at a radius greater than thatlofthe toothed part of the ring for transmitting; torque.` between the two said rigid drive members.

cushioned" gear assembly comprising a. rigidihubmember; a rigid toothed gear ring surrounding the' hub' member and therewith deningff an annular space, cushioning means in said space and having engagement with the hub member and the. ring for transmission of torque between the two, a rigid drive memberl having driving' connectionV t'o the toothedu ring'lL and of: greater radial extent than. the tooth' portion.' o'f thev ring, a rigiddrive. memberv securedon. the hub member in close proximity 'to theirstsaid drive member, and cushioning means. ata radi" greater-'than that'of'the` toothed part' of' th'eriig. for." transmitting torque between. the'l two' said? rigid 'drive members;

THOMASl L'. FAWIcK-i REFERENCES 5 crrEn- VvThe following., references.- are of.- recordz inf: theille-'of this patent:

Number. Name' Date.:l

1,760,492. HalllVIay.v 27,'.1930v 1,910,179 P'annenstieh'l" May 23;.193f' 1,928,763 Rosenberg Oct.' 32,1933@ 1,997,488 Henry, Apr; 9; 19'35l 2,044,392 Lord' June 16;.1936 2',3'90,'168` Pi'ot .Dec. 4,'.1945y FOREIGN PATENTS 1 Number.` y Country Date- A 459,216'y GreatBritain o'f 1935 

